1. Field of the Invention
The present invention relates to a self-light-emitting device having an EL element formed on an insulator and structured to have an anode, a cathode, and a light-emitting organic material that provides electro luminescence (hereinafter referred to as an organic EL material) sandwiched therebetween, an electric apparatus having such a self-light-emitting device as a display unit (a display or a monitor), and a method of manufacturing thereof. It is to be noted that such an EL display device is sometimes referred to as an OLED (organic light emitting diode).
2. Description of the Related Art
These days, display devices using EL elements as self-light-emitting devices utilizing electro luminescence of a light-emitting organic material (EL display devices) are actively developed. Since an EL display device is of a self-light-emitting type, unlike the case of a liquid crystal display device, no backlight is necessary. Further, since the view angle is wide, an EL display device is expected to be promising as a display unit of an electric apparatus.
EL display devices are broken down into two: a passive type (simple matrix type); and an active type (active matrix type), both of which have been actively developed. Particularly, active matrix EL display devices are attracting attention these days. With regard to EL materials to be an EL layer which can be the to be the center of an EL element, low molecular weight organic EL materials and macromolecular (polymer) organic EL materials have been studied.
A film of an EL material is formed by ink jetting, evaporation, spin coating, or the like. With regard to evaporation, the location of film formation is controlled using a mask. Here, there is a problem in that the EL material does not pass through the mask, but instead is deposited on the mask.
The present invention has been made in view of the above, and an object of the present invention is therefore to provide means for selectively forming a film of an EL material without a waste by evaporation where the EL material is controlled by an electric field using a mask. Another object of the present invention is to improve the accuracy of controlling the location of film formation. Still another object of the present invention is to provide a self-light-emitting device using such measures and a method of manufacturing thereof. Yet another object of the present invention is to provide an electric apparatus having such a self-light-emitting device as a display unit.
In order to attain the above objects, according to the present invention, voltage is applied to the mask and a pixel electrode on which film formation is to be performed.
According to the present invention, the EL material is provided in a sample boat. By vaporizing and charging the EL material, it is discharged from an opening of the sample boat due to the vaporization, and, before it reaches a substrate, its direction of progress is controlled by the electric field generated by voltage applied to the mask, and thus, the location of deposition of the EL material can be controlled.
A plurality of masks may be used. For instance, an electric field is generated by voltages applied to a first mask and a second mask respectively, thereby controlling the direction of progress of the EL material and controlling the location where it is deposited.